Siemens FS20 - Page 80

Planning detector lines
Planning an FDnet detector lin
e
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Building Technologies
008843_v_en_
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Fire Safety
2015
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Verification
Verify the ↑ maximum current connection factor reserve by means of the diagram.
To do so, proceed as follows:
1. In the diagram for four loops, draw a vertical line at the address connection
factor AK = 18.
2. Draw a horizontal line in the intersection point with the 150 ohm curve.
3. Determine the maximum current connection factor reserve (MK_res). In this
example, it is 258.
4. Check whether the maximum current connection factor reserve (MK_res) is
higher than the calculated maximum current connection factor (MK). In this
example, the maximum current connection factor reserve (MK_res = 258) is
higher than the maximum current connection factor (MK = 200).
a The line may be operated in this way.
Exemplary diagram for a ↑ line card with four loops
Figure 25: Example for the verification of the ↑ maximum current connection factor reserve (MK_res)
Information
The intersection point of AK and the resistance curve must be below the line
'MK_limit' (admissible range for the ↑ maximum current connection factor). Any
intersection points above that line are inadmissible.
If the maximum current connection factor reserve (MK_res) is lower than the
calculated maximum current connection factor (MK), the line must not be operated.
In that case, you will have to change the line assignment and calculate again.
0
50
100
150
200
250
300
350
1
2
5
O
h
m
1
5
0
O
h
m
1
8
0
O
h
m
2
1
0
O
h
m
2
4
0
O
h
m
0
10
20
30
40
50
60
AK
MK_res
M
K
_
l
i
m
i
t
(
1
2
5
m
A
)
258
18